coupe

Hello all, I was just talking to a friend that owns a 944S. We were discussing Turbo boost pressures. I was telling him that I measured my boost pressure and the best that I could come up with was 10 psi or 0.69 Bar.

He mentioned that perhaps I have a Japanese market car and that the DME has 4 preset fuel maps that can be selected by adjusting jumper settings. He mentioned that the Japanese and Californian models had the least of power due to tough emission laws.

Can anyone shed more light on these fuel map jumper settings?

Jeremy Himsel

Coupe,

While I can't speak for a Japanese model, my car is a California car and made the correct boost when it was stock. I wasn't aware that Porsche sent many 951's to Japan.

threesticks1

Hey Coupe: There are four maps in the DME that all can be accessed by using different jumpers and adapters in the correct locations.

The best map to use is the ROW ( Rest of the World). That is what I am using and the car seems to run better. I haven't noticed anymore boost, just improved throttle response and better drivability. The ROW map runs slightly richer. This will be hard on your cat if you still have one. The ROW cars don't have a cat, they have a muffler in the same location as the cat.

To access the ROW map you need an adapter plug 944.612.421.00. It really is just a 1.8K Ohm resistor with the correct connector. I ordered mine from the dealer for about $18. Un plug the altitude compensator and plug in the adapter in its place. You then have to disconect the O2 sensor in the engine compartment and jumper between pins 1 and 3 on the DME harness. This grounds out the input from the O2 sensor and this in combination with the adapter plug tells the DME to use the ROW maps. Remember to disconect the battery before starting anything involving the electrical.

If you have the factory manuals and PET all of the info is there, you just have to dig around for it.

Hope that this helps.

TonyG

threesticks1

Where is the altitude compensator?

TT

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> Hey Coupe: There are four maps in the DME that all can be accessed by using different jumpers and adapters in the correct locations. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">There are four possible combinations using jumpers but there are only three sets of maps in the chips for the 944/951. The idle and WOT fuel/ignition map sets are identical for the 86 951 chip (except for one cell in an idle ignition map). The differences are in the part throttle fuel/ignition maps. These differences are mainly in the low load ranges (where emissions are tested).

Danno

Here's a picture comparing the USA vs. the ROW partial-throttle fuel-maps:
<img src="http://www.gururacing.net/ImagesMisc/PartialThrottleFuelMaps.jpg" alt=" - " />

The USA map is actually used by Canada,Japan, and Australia as well. The Sweden&Swiss have their own map, then there's a ROW map for all those who've been left out. The ROW and the Swede/Swiss maps are the same, so I left one off.

The USA map is a lot richer than the ROW map, I guess because of the O2-sensor. It will tend to lean out mixture to 14.7:1. The ROW cars without catalytic and O2-sensor needs to be mapped a little more precisely to the actual flow-patterns of the car.

All the WOT maps are identical, so I doubt there's an power-differences between a US and ROW car. Although I've seen the Euro-951 marketed as a 220bhp car while the US got a 217bhp version. I would guess that this is the difference from the catalytic.

"Where is the altitude compensator?"

It's located on the side of the passenger footwell. It is a binary device that triggers a straight 6.3% fuel-reduction at 3000ft.

coupe

Well that's great information. I'll have to take a closer look at my PET and the workshop manuals.
I replaced all the rubber hoses from the turbo to inter cooler and J boot air box a couple of days ago.

I may may be loosing 1.5~ 2 psi of boost due to a leak after the Turbo charger. I'll have to pressure test the intake system, before I play around with the fuel maps on the DME computer.

The ambient temperatures are over 110 F, maybe this would also contribute to loss of power.

My waste gate is the original, and the top cover is being held by 2 bolts. I'll have to get under there and see what the issue is.

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">All the WOT maps are identical, so I doubt there's an power-differences between a US and ROW car.

DANNO </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Danno with a set of your Guru racing chips, would I still have to play around with pin settings?

The cat is long gone, but the O2 sensor is still in there. I'm not sure if it is working, since the car is a little rough at idle.

Thanks everyone. <img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />

Olli Snellman

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">The USA map is a lot richer than the ROW map, I guess because of the O2-sensor. It will tend to lean out mixture to 14.7:1. The ROW cars without catalytic and O2-sensor needs to me mapped a little more precisely to the actual flow-patterns of the car. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Danno,
our gang here in Finland (with Guru chips, soon you know what ) will have custom made test pipes.
Since most of our cars are US spec cars, what fuel map do you recommend to be used in our cars when cats are removed?? How about these two euro spec ones we have??